Narwhals are social whales that live in frigid Arctic waters. Narwhal means "corpse whale" in Old Norse; this is perhaps a
description of their skin, which is bluish-gray with white blotches
(young narwhals are brown).

Anatomy: Males have a very long, hollow, spiral tooth. Narwhals can grow to be about 16 feet (4.5 m) long (not counting the tooth), and weigh about 1.8 tons (1.6 tonnes).